The Linux sg3_utils package
The Linux sg3_utils
package
Introduction
The sg3_utils package contains utilities that sendSCSI commands to devices. As well as devices on transports traditionally
associated with SCSI (e.g. Fibre Channel (FCP), Serial Attached SCSI (SAS) and
the SCSI Parallel Interface(SPI)) many other devices use SCSI command sets.
ATAPI cd/dvd drives and SATA disks that connect via a translation layer or a
bridge device are examples of devices that use SCSI command sets.
SCSI
command sets are divided into a common set and several device class specific
sets. The common set of commands is referred to as the SCSI Primary Commands
(SPC) with SPC-3 being the most recent standard. The mandatory SCSI INQUIRY
command is defined in SPC-3. The SCSI Block Commands (SBC) cover direct access
devices such as disks. The MultiMedia Commands (MMC) cover CD, DVD and BD drives
and the media within them. SCSI command sets and transport definitions can be
found at the www.t10.org . That site includes
this helpful diagrammatic overview: www.t10.org/scsi-3.htm .
The
sg3_utils package was developed for the
Linux kernel 2.4 and 2.6 series and is still being enhanced. An earlier package
called sg_utils targeted the Linux kernel 2.2 series with some support for the
2.0 series. See an earlier version of this web page
for further information about sg_utils. This document describes version 1.31 of sg3_utils . The majority of these utilities
have been ported to the FreeBSD, Solaris, Tru64 and the Windows operating
systems.
In the Linux kernel (lk) 2.4 series most of these utilities must
be used with a SCSI generic (sg) driver device name (e.g. /dev/sg0). In the lk 2.6 series almost all
of these utilities can be used with the primary device names as well (e.g. /dev/sda, /dev/scd0, /dev/st0 and /dev/hdd (if it is an ATAPI device)). From
lk 2.6.28 bsg devices can also be used (e.g. /dev/bsg/3:0:0:0 ).
A list of SCSI and storage utility programs can be found on this tools page.
Contents of sg3_utils
Thispackage contains over 40 utilities, their "man" pages, build files and general
documentation. The utilities have a command line interface which in general has
this form:
UTILITY_NAME
[OPTIONS] DEVICE
No more than one DEVICE name can be given (and in
a few cases, no DEVICE name is required). Below is a listing in alphabetical
order of the main utilities in the sg3_utils package:
| Utility name |
Main SCSI commands invoked |
CLI |
Ported |
Notes |
| sginfo [legacy, use sdparm] |
MODE SENSE/SELECT, READ DEFECT |
adhoc |
symbolic decoding (optional changing) of mode pages. Can also output (disk) defect lists. Port of older scsiinfo utility. |
|
| sgm_dd |
READ, WRITE |
dd |
sg_dd variant that uses memory mapped IO (only on Linux sg devices) |
|
| sgp_dd |
READ, WRITE |
dd |
sg_dd variant that uses POSIX threads |
|
| sg_dd |
READ, WRITE |
dd |
Unix dd command variant, uses SG_IO ioctl to send SCSI commands to copy data. See the sg_dd page. Newer ddpt utility adds features and is ported to "f,s,w" |
|
| sg_decode_sense |
getopt |
f,s,t,w |
decodes sense data given as a string of hexadecimal bytes or in binary |
|
| sg_emc_trespass |
MODE SELECT |
adhoc |
utility specialized for EMC Clariion series |
|
| sg_format |
FORMAT |
getopt |
f,s,t,w |
format or resize a SCSI disk |
| sg_get_config |
GET CONFIGURATION |
getopt |
f,s,t,w | fetch features and profiles of a cd/dvd drive and/or its current media |
| sg_get_lba_status |
GET LBA STATUS |
getopt |
f,s,t,w |
logical block provisioning support |
| sg_ident |
REPORT/SET IDENTIFYING INFORMATION |
getopt |
f,s,t,w | default is to report (fetch) the device identifier. With the '--set' option a new identifier is sent to the device. |
| sg_inq |
INQUIRY |
getopt+ |
f,s,t,w | fetch standard response, VPD pages or version descriptors. Also can perform IDENTIFY (PACKET) DEVICE ATA command. VPD page decoding also performed by sg_vpd and sdparm. |
| sg_logs |
LOG SENSE |
getopt+ |
f,s,t,w | fetch log sense pages, decode standard and some vendor pages |
| sg_luns |
REPORT LUNS |
getopt |
f,s,t,w | fetch luns reported by a device (lun 0 or "well known lu") |
| sg_map |
INQUIRY |
adhoc |
shows mapping between sg devices and primary device node (if any). In lk 2.6 see lsscsi . |
|
| sg_map26 |
getopt |
maps between single Linux sg device and primary device node (and vice versa). Also does mapping in to, and out of, sysfs. For the Linux 2.6 series. |
||
| sg_modes |
MODE SENSE |
getopt+ |
f,s,t,w | fetch mode pages (output mainly in hex, to decode output use sdparm) |
| sg_opcodes |
REPORT SUPPORTED OPERATION CODES |
getopt+ |
f,s,t,w |
fetch supported SCSI commands or supported task management functions |
| sg_persist |
PERSISTENT RESERVE IN/OUT |
getopt |
f,s,t,w | control persistent reservations and report reservation status |
| sg_prevent |
PREVENT ALLOW MEDIUM REMOVAL |
getopt |
f,s,t,w | control media removal, mainly for those SCSI devices which have removable media (e.g. CD/DVD and tape drives) |
| sg_raw |
<user specified> |
getopt |
f,s,t,w |
send user supplied cdb |
| sg_rbuf |
READ BUFFER |
getopt+ |
read from SCSI device cache. Typically for testing the SCSI transport (for throughput or errors) |
|
| sg_rdac |
MODE SENSE/SELECT |
adhoc |
f,s,t,w | display or modify RDAC redundant controller mode page |
| sg_read |
READ |
dd |
read continually from same offset. Syntax similar to sg_dd (without write side). Can test SCSI device cache and transport performance. |
|
| sg_readcap |
READ CAPACITY |
getopt+ |
f,s,t,w | fetch the number of blocks and the individual block size for disks and CD/DVD media |
| sg_read_buffer |
READ BUFFER |
getopt |
f,s,t,w |
read descriptors or data |
| sg_read_long |
READ LONG |
getopt |
f,s,t,w | read data from given LBA which includes the block and ECC data. |
| sg_reassign |
REASSIGN BLOCKS |
getopt |
f,s,t,w | reassign a LBA from one sector on a disk (typically damaged) to a new (spare) sector. User data copied if it is recoverable. |
| sg_referrals |
REPORT REFERRALS |
getopt |
f,s,t,w | report data segment accessibility from target port groups |
| sg_requests |
REQUEST SENSE |
getopt |
f,s,t,w | fetch sense data from the given device. Modern uses include getting a progress indication (e.g. during a format) or finding the power condition state. |
| sg_reset |
- |
adhoc |
Issue a driver, (SCSI) bus or device (target or lun?) reset. |
|
| sg_rmsn |
READ MEDIA SERIAL NUMBER |
getopt |
f,s,t,w | Relatively new command added to SPC-3. Format of response is vendor specific so this utility outputs it in hex (default) or binary. |
| sg_rtpg |
REPORT TARGET PORT GROUPS |
getopt |
f,s,t,w | Specialized for multi-ported SCSI devices where one port (or a group of them) is preferred for IO over another (or others). |
| sg_safte | READ BUFFER | getopt | f,s,t,w | fetch information from a SAF-TE processor |
| sg_sat_identify |
ATA PASS-THROUGH | getopt |
f,s,t,w |
Send ATA IDENTIFY DEVICE or IDENTIFY PACKET DEVICE commands via the SAT ATA PASS-THROUGH (16 or 12) SCSI command. |
| sg_sat_phy_event |
ATA PASS-THROUGH | getopt |
f,s,t,w | Sends an ATA READ LOG EXT command via a SAT to fetch log page 11h which contains SATA phy event counters. |
| sg_sat_set_features |
ATA PASS_THROUGH |
getopt |
f,s,t,w | Sends ATA SET FEATURES command via SAT |
| sg_scan [.c.linux] |
[INQUIRY] |
adhoc |
Linux only |
maps each sg device name to the corresponding numeric <host, channel, target, lun> tuple. In lk 2.6 series the "lsscsi -g" command is similar. |
| sg_scan [.c.win32] |
[INQUIRY] |
getopt |
win32 only |
shows one device per line, with the device's various names and INQUIRY response string on that line. |
| sg_senddiag |
SEND DIAGNOSTIC |
getopt+ |
f,s,t,w | Issues either a default self test or a short/extended foreground/background self test. With no arguments it uses RECEIVE DIAGNOSTIC RESULTS to list all supported diagnostic pages. |
| sg_ses |
SEND/RECEIVE DIAGNOSTIC |
getopt |
f,s,t,w | Fetches status diagnostic pages from, and sends some control pages to, a SCSI Enclosure Services (SES) device. |
| sg_start |
START STOP UNIT |
getopt+ |
f,s,t,w | Controls the power condition state of a SCSI device. Primary use is to spin up and down SCSI disks. Can also load and eject removable media. |
| sg_stpg |
SET TARGET PORT GROUPS | getopt |
f,s,t,w | Specialized for multi-ported SCSI devices where one port (or a group of them) is preferred for IO over another (or others). |
| sg_sync |
SYNCHRONIZE CACHE |
getopt |
f,s,t,w | Causes disk caches to be flushed to media |
| sg_test_rwbuf |
READ/WRITE BUFFER |
getopt |
Random pattern written to SCSI device buffer then read back and checked. Used in testing for data corruption. |
|
| sg_turs |
TEST UNIT READY |
getopt+ |
f,s,t,w | Issue one or more Test Unit Ready commands. Can be used to time SCSI command overhead. |
| sg_unmap |
UNMAP |
getopt |
f,s,t,w |
logical block provisioning support ("Trim" in the ATA world) |
| sg_verify | VERIFY | getopt |
f,s,t,w | reads indicated blocks on a SCSI disks, stops on the first error found. Does not yield any data. Useful for media scans. |
| sg_vpd |
INQUIRY |
getopt |
f,s,t,w |
Decodes standard and some vendor Vital Product Data (VPD) pages. |
| sg_write_buffer |
WRITE BUFFER |
getopt |
f,s,t,w |
write data; can be used to download firmware |
| sg_write_long |
WRITE LONG |
getopt |
f,s,t,w | writes to a LBA, data which includes the block and ECC data. Suitable data typically fetched by prior sg_read_long utility. |
| sg_write_same |
WRITE SAME |
getopt |
f,s,t,w |
writes a single block to one or more (consecutive) LBAs. Also supports some logical block provisioning options. |
| sg_wr_mode |
MODE SELECT |
getopt |
f,s,t,w | writes mode pages supplied in ASCII hex (e.g. from "sg_modes -r") to the SCSI device. See sdparm for another method of setting mode page parameters. |
More SCSI commands may be
issued than shown in the Main SCSI commands
invoked column. For example many utilities issue a SCSI INQUIRY command
to find out the peripheral device type of the given device. Some SCSI commands
listed above are only relevant to a specific device type (e.g. FORMAT UNIT for
disks) and should not be sent to a device belonging to another peripheral device
type. See the COVERAGE file in the main directory for a more exhaustive list of
SCSI (and ATA) commands issued by the sg3_utils utilities.
The source
code for all the main utilities in table 1 is found in the src sub-directory. Prior to version 1.25
this source was found in the main directory. Each utility listed has a
corresponding "man" page in the doc
sub-directory.
The CLI column
indicates what kind of Command Line Interface the utility has. Recent utilities
have a CLI based on the getopt_long() function which offers both long option
names (e.g. "--verbose") and a short
form (e.g. '-v'). Both forms can
take an argument. Experience has led to consistent use of various options such
as "--help", "--verbose" and "--version" across these utilities.
Utilities with this type of CLI are marked with "getopt" in the CLI column. The
original utilities had an "ad hoc" type CLI that unfortunately lacked
consistency and had a mix of long and short forms (with the long form sometime
prefixed with "-" and on other occasions with "--"). Utilities with this type of
CLI are marked with "adhoc". There is also a group of utilities that are related
to the Unix dd command and share its
quirky CLI. Finally a group of well used utilities with ad hoc command line
interfaces had a getop_long() based interface added in sg3_utils version 1.23 .
This group contains significant utilities such as sg_inq, sg_logs and sg_modes.
The default CLI for this group is "getopt" but by using "--old" or "-O" as the first option the
older ad hoc options can be used. This group will default to the older ad hoc
interface if the environment variable SG3_UTILS_OLD_OPTS is defined. Utilities
with this type of CLI are marked with "getopt+".
If the Ported column is empty then the utility is only
found in Linux. Support for other ports is indicated by "f" for FreeBSD, "s" for
Solaris, "t" for Tru64 (OSF), and "w" for Windows. See the README,
README.freebsd, README.solaris, README.tru64, README.win32, and the INSTALL
files for more information.
| Utility |
Main SCSI commands invoked |
directory |
CLI |
Ported |
Notes |
| hxascdmp |
- |
utils |
adhoc |
f,s,w |
converts stdin (assumed binary) to ASCII hex and ASCII, sending its output to stdout (like the Unix od command and hexdump in BSD) |
| rescan-scsi-bus.sh |
- |
archive |
adhoc |
copy of Kurt Garloff's useful script |
|
| scsi_inquiry |
INQUIRY |
examples |
adhoc |
uses deprecated SCSI_IOCTL_SEND_COMMAND ioctl |
|
| sdparm |
MODE SENSE/SELECT, INQUIRY |
--> |
getopt |
f,s,t,w |
was in the sg3_utils package for a short time; now in own package, see sdparm . sdparm manipulates mode pages, reads VPD pages and sends simple commands |
| sg_chk_asc |
- |
utils |
getopt |
f,s |
check asc/ascq codes from www.t10.org page against sg3_utils internal table |
| sg__sat_identify |
ATA PASS-THROUGH |
examples |
adhoc |
Simpler version of sg_sat_identify that uses the Linux SG_IO ioctl directly. |
|
| sg__sat_phy_event |
ATA PASS-THROUGH | examples |
getopt |
Simpler version of sg_sat_phy_event | |
| sg__sat_set_features | ATA PASS_THROUGH | examples | getopt |
Simpler version of sg_sat_set_features that uses the Linux SG_IO ioctl directly. |
|
| sg_simple1,2,3,4,5 |
INQUIRY, TEST UNIT READY |
examples |
adhoc |
Simple code examples of using the scsi generic (sg) driver interface |
|
| sg_simple16 |
READ |
examples |
adhoc |
Simple code example of sending a 16 byte cdb SCSI READ command |
The directory column contains the name of the
sub-directory in which the utility source code is found. Source code in these
sub-directories may, in some cases, be built by Makefiles in those
sub-directories. See the README file for more information. Not all the code in
the examples sub-directory is listed
in table 2. Some utilities in these sub-directories have "man"
pages.
This paragraph contains Linux specific information. All utilities
that issue SCSI commands and that appear in table 1, with the exception of
sgp_dd, issue SG_IO ioctls. The sgp_dd utility issues SCSI commands using the sg
driver's asynchronous ( write()/read() ) interface to device nodes that have the
sg driver's major device number (i.e. "char" major 21). This means that all
utilities in table 1 are "safe" with any given device node. If the device node
does not support the SG_IO ioctl then that is reported and the utility exits.
sg3_utils version 1.27 introduces support for bsg: the ./configure stage of the package build
needs to find /usr/include/linux/bsg.h and at run time
the bsg char device needs to be present in the /proc/devices pseudo file. Then if the
device given to utility has a char major that matches bsg then the SG_IO ioctl
is used with the sg version 4 interface.
Irrespective of the device node
used to access a device, care should be taken not to interfere with a device
while it is "active". For example invoking a "sg_format -F" utility on a disk with one
or more of its partitions in use (e.g. a mounted file system) is obviously
unwise.
Sub directories
The sg3_utilspackage has several sub-directories that are outlined in the following
paragraphs. Prior to sg3_utils version 1.25 the Makefile in the main directory
only build code from the main directory (thus, for example, it did not build the
code in the examples sub-directory).
From sg3_utils version 1.25 the build infrastructure files (i.e. configure.ac, Makefile.am, src/Makefile.am,
include/Makefile.am, lib/Makefile.am and doc/Makefile.am) build code found in the
lib, src, doc and include sub-directories.
The archive sub-directory contains code that was
recently displaced from the src
sub-directory. To reduce the size of the overall package, the amount of code
carried forward from one release to the next is reduced from time to
time.
The debian sub-directory
contains rules for building a Linux debian package (i.e. ".deb") from the source
code in the src sub-directory. There
is a build_debian.sh shell script in
the main directory that can be executed to build a debian package. Note that
various distributions that use debian packages and include sg3_utils may vary
their build scripts from the ones supplied in this sub-directory.
The
doc sub-directory contains a README file which contains urls of web
documents related to sg3_utils. The html code used to be present in this
sub-directory but it was bloating the package. From sg3_utils version 1.25 the
source for the man pages is found in this sub-directory. Those files end with
the extension ".8" indicating that they are grouped in the system administration
command section. Information common to all utilities has been placed in a man
page called sg3_utils.
The examples sub-directory contains relatively
simple code examples that may be useful to those trying to use the SCSI
pass-through mechanism in the supported operating systems. It also shows the
usage of the common library code. There is a test script and data for the sg_persist utility. There is also some
test data for sg_reassign and sg_senddiag utilities.
The getopt_long sub-directory contains code for
implementing the getopt_long() library call which is not present in Tru64
(osf).
The include sub-directory
was introduced in version 1.25 and contains C header files. These header files
are common to many utilities in this package. The header files are written in
such a way so that they compile cleanly in C++ .
The lib sub-directory was introduced in version
1.25 and contains C source files that are used by many of the utilities.
Depending on the target architecture and configure options, these files may be
build into a library. The source files are written to compile cleanly as C or
C++.
The src sub-directory was
introduced in version 1.25 . It contains the C source code for each of the main
utilities. In most cases each utility has a single C source file (e.g. sg_inq.c for the sg_inq utility). In some cases there may
be an additional helper file (e.g. the sg_vpd utility has both sg_vpd.c and sg_vpd_vendor.c).
The scripts sub-directory contain shell scripts for
common chores and for checking compliance. Unlike most utilities in the src sub-directory, many of these scripts
can take multiple device names. For example: 'scsi_stop /dev/sd*' will attempt to stop
(spin down) all SCSI disks. See the README file in that directory for more
information.
Exit status
These command lineutilities run as processes and finish with an exit status of 0 when successful.
Prior to version 1.21 all errors yielded an exit status of 1. Having finer grain
error reporting via the exit status from relatively low level sg3_utils
utilities allows higher level scripts and other program wrappers to do more
useful error processing.
From version 1.22 the exit status value is one
of:
| Exit status |
Description |
| 0 |
no error detected. Utility completed successfully |
| 1 |
syntax error in command line options or their arguments, or an illegal combination of options |
| 2 |
the device reports that it is not ready for the operation requested. The device may be in the process of becoming ready (e.g. spinning up but not at speed) so the utility may work a little while later |
| 3 |
the device reports a medium or hardware error (or a blank check). For example an attempt to read a corrupted block on a disk will yield this value |
| 5 |
the device reports an "illegal request" with an additional sense code other than "invalid operation code". This is often a supported command with a field set requesting an unsupported capability. For commands that require a "service action" field (e.g. READ CAPACITY(16) ) this value can indicate that the command is not supported |
| 6 |
the device reports a "unit attention" condition. This usually indicates that something, unrelated to the requested command, has occurred (e.g. a device reset) potentially before the current SCSI command was sent. The requested command has not been executed by the device. Note that unit attention conditions are usually only reported once by a device |
| 9 |
the device reports an illegal request with an additional sense code of "invalid operation code" which means that the device doesn't support the requested command |
| 11 |
the device (or transport) reports an aborted command. In some cases this can be caused by congestion on the transport and retrying the command may be successful |
| 15 |
the utility is unable to open, close or use the given device. The given file name could be incorrect or there may be permission problems. Adding the '-v' option may give more information |
| 20 |
the DEVICE reports it has a check condition but "no sense". Some polling commands (e.g. REQUEST SENSE) can react this way. It is unlikely that this value will occur as an exit status |
| 21 |
the device reports a "recovered error". The requested command was successful. Most likely a utility will report a recovered error to stderr and continue, probably leaving the utility with an exit status of 0 |
| 33 |
the command sent to the device has timed out. This occurs in Linux, in other ports a command timeout will appear as a transport (or OS) error |
| 97 |
the response to a SCSI command failed sanity checks |
| 98 |
the device reports it has a check condition but the error doesn't fit into any of the above categories |
| 99 |
any errors that can't be categorized into values 1 to 98 may yield this value. This includes transport and operating system errors |
Many of the above exit statuses will be
repeatable so executing the utility again with one or more '-v' options may yield more information.
Unit attentions (exit status 6) are only reported once per condition. Notice
that some of the lower exit status values (e.g. 2 to 11) correspond to the SCSI
sense key values. For examples of bash scripts that use these exit values see
the script files in the scripts
sub-directory.
Changing mode page
settings
SCSI devices store settings (meta-data) that may possibly be changed by the user program (called the "application client" in SCSI jargon) in
mode pages. It is a common requirement to find mode page settings and in some
cases change them. An example is the Writeback Cache Enable (WCE) bit in the
Caching mode page of SCSI disks. Usually the manufacturer's default setting for
WCE is set (on) however in some RAID configurations it may be cleared (off).
Generic command line tools to change mode page settings tend to be
difficult to use (which in some small part is due to the SCSI rules for
manipulating mode pages). Here is a list of some Linux utilities for changing
mode pages:
- scsiinfo (old utility): awkward
command line interface that requires a double invocation (first to get, second
to set). Only mode page fields that the utility knows about can be changed. - sginfo (sg3_utils version of
scsiinfo): same awkward interface as scsiinfo but the mode pages are more up to
date. Supports other modern features such as mode subpages. - sg_wr_mode (sg3_utils): low level
mode page settings based on ASCII hex representation. Used with sg_modes to get
a mode page in raw form and assumes ACSII hex will be edited. Low level but
general. - sdparm (sdparm): uses acronyms (e.g.
WCE) or numeric addressing to fetch and/or change mode page settings. Permits
mode pages to be reset to their default settings. The user can choose whether
changes are also made to the "saved" mode page values. The numeric addressing
allows arbitrary fields to be changed (i.e. sdparm doesn't need to know about a
mode page or its field structure in advance). - sgmode (scsirastools): interactive
utility for setting mode pages with data held in preset ".mdf" files. Useful to
setting a large number of disks to preset mode page values but awkward for
manipulating a specific mode page field. - hdparm (hdparm): abstracts over ATA
(mainly) and SCSI (where convenient) disks. Write caching can be turned on and
off but that is one of the few mode page fields that can be changed on a SCSI
device. - blktool (blktool): a newer and
cleaner version of hdparm which targets the Linux kernel 2.6 series. For SCSI
devices only a relatively small (but important) number of mode page fields can
be changed. - vendor specific (e.g. seatools from Seagate): several vendors have utilities
like this. Worth investigating and often useful with disks from other
manufacturers. Vendor extensions can be controlled (e.g. Seagate's
desktop/server mode (also see sdparm's man page about this particular
feature)).
your needs.
Aside: device meta-data that cannot be changed by the user is
often placed in Vital Product Data (VPD) pages. The VPD pages can be accessed
via the SCSI INQUIRY command. The sg_vpd utility in this package and sdparm utility list the contents of various VPD pages.
Examples
Most of theseexamples use Linux device names. See the device
naming page for appropriate device names in other supported operating
systems.
The fundamental SCSI command whose support is mandatory for all
SCSI devices is INQUIRY. All devices should respond to a "standard" (i.e. when
no Vital Product Pages are requested) INQUIRY.
$ sg_inq /dev/sda
standard
INQUIRY:
PQual=0 Device_type=0 RMB=0 version=0x03
[SPC]
[AERC=0] [TrmTsk=0] NormACA=0 HiSUP=1
Resp_data_format=2
SCCS=0 ACC=0 TGPS=0 3PC=0
Protect=0
BQue=0 EncServ=0 MultiP=0 MChngr=0
[ACKREQQ=0] Addr16=1
[RelAdr=0] WBus16=1 Sync=1 Linked=1
[TranDis=1] CmdQue=1
Clocking=0x3 QAS=0 IUS=0
length=144 (0x90) Peripheral device type: disk
Vendor
identification: SEAGATE
Product identification: ST318451LW
Product
revision level: 0003
Unit serial number: xxxxxxxxx
Some
SCSI devices have version descriptor information showing which standards (and
drafts) they support:
$ sg_inq -d
/dev/sdb
standard INQUIRY:
PQual=0
Device_type=0 RMB=0 version=0x03 [SPC]
[AERC=0]
[TrmTsk=0] NormACA=0 HiSUP=0 Resp_data_format=2
SCCS=0
ACC=0 TGPS=0 3PC=0 Protect=0
BQue=0 EncServ=0 MultiP=0 MChngr=0
[ACKREQQ=0] Addr16=1
[RelAdr=0] WBus16=1 Sync=1 Linked=1
[TranDis=1] CmdQue=1
Clocking=0x0 QAS=0 IUS=0
length=96 (0x60) Peripheral device type: disk
Vendor
identification: FUJITSU
Product identification: MAM3184MP
Product
revision level: 0106
Unit serial number: xxxxxxxxx
Version descriptors:
SAM-2
(no version claimed)
SPI-3 T10/1302-D revision 10
SPC ANSI
X3.301:1997
SBC T10/0996-D revision
08c
Many modern SCSI devices also support "Vital Product Data"
(VPD) pages. Here is a request to list available VPD pages:
$ sg_inq -e /dev/sg1
VPD INQUIRY,
page code=0x00:
[PQual=0 Peripheral device type:
disk]
Supported VPD pages:
0x0 Supported VPD pages
0x80 Unit serial number
0x83 Device identification
For displaying VPD pages, sg_vpd
(or sdparm) may be a better choice than sg_inq as sg_vpd has a simpler, less
cluttered command line interface and additional support for vendor specific VPD
pages.
# sg_vpd /dev/sdh
Supported
VPD pages VPD page:
Supported VPD pages [sv]
Unit
serial number [sn]
Implemented operating definition (obs)
[iod]
Device identification [di]
The
following displays a subset of the device identification VPD page, namely the
designators for the target port:
#
sg_vpd --page=di_port /dev/sdh
Device Identification VPD page:
Target
port:
designator type: Relative target port, code_set: Binary
transport: Serial Attached SCSI (SAS)
Relative target port: 0x1
designator type: NAA, code_set: Binary
transport: Serial Attached SCSI
(SAS)
0x5222222000000f9e
The sg_scan and sg_map utilities show
the relationships between Linux sg devices, their <bus, channel, target,
lun> tuples and their primary device node names:
Example: given these 3 SCSI devices:
$
cat /proc/scsi/scsi
Attached
devices:
Host: scsi1
Channel: 00 Id: 00 Lun: 00
Vendor:
SEAGATE Model: ST318451LW Rev: 0003
Type: Direct-Access ANSI
SCSI revision: 03
Host: scsi2
Channel: 00 Id: 04 Lun: 00
Vendor:
PIONEER Model: DVD-ROM DVD-303 Rev: 1.10
Type: CD-ROM ANSI
SCSI revision: 02
Host: scsi2
Channel: 00 Id: 06 Lun: 00
Vendor:
YAMAHA Model: CRW4416S Rev: 1.0g
Type: CD-ROM ANSI
SCSI revision: 02
then the output from sg_scan is:
$
sg_scan
/dev/sg0:
scsi1 channel=0 id=0 lun=0 type=0
/dev/sg1: scsi2 channel=0 id=4
lun=0 type=5
/dev/sg2:
scsi2 channel=0 id=6 lun=0 type=5
INQUIRY data can be added to that output with the '-i' option. The sg_map utility shows the
mapping between scsi generic (sg) devices and the corresponding primary device
node. For some peripheral device types, SCSI enclosures for example, there is no
mapping and the enclosure device must be accessed via a sg device node.
$ sg_map
/dev/sg0 /dev/sda
/dev/sg1 /dev/scd0
/dev/sg2 /dev/scd1
of kernels sg_scan and sg_map are less important as most utilities in the
sg3_utils package can be issued directly against the primary device node (e.g.
/dev/sda). However the sg driver is
still needed to "talk" to devices such as enclosures which have no specialized
driver in Linux.
Some examples of the use of the sg_persist utility can
be found in the source tarball in examples/sg_persist_tst.sh . Some more
information about that utility can be found in examples/transport_ids.txt .
The
Windows port has its own sg_scan utility which attempts to list the common
storage devices, one per line. Volume names corresponding to a storage device
(or a partition on that device) are shown in brackets. Here are two examples,
the second one adds a bus type field:
$ sg_scan
PD0
[C] FUJITSU MHY2160BH 0000
PD1
[DF] WD 2500BEV External 1.05 WD-WXE90
CDROM0
[E] MATSHITA DVD/CDRW UJDA775 CB03
$ sg_scan -b
PD0
[C] <Ata > FUJITSU MHY2160BH 0000
PD1
[DF] <Usb > WD 2500BEV External 1.05 WD-WXE90
CDROM0
[E] <Atapi> MATSHITA DVD/CDRW UJDA775 CB03
The PD0 device name is a shortened
form of PhysicalDrive0 and corresponds to volume C: . The USB connected PD1
contains two partitions recognized by Windows and they are D: and F: . Apart
from the storage device names PD<n> and CDROM<n>, there is
TAPE<n> for tape drives.
libsgutils
The variousutilities in this package were found to have a lot of common code (e.g. use of
the SCSI INQUIRY command and SCSI error processing). So a library called libsgutils has been created. Following Unix
conventions the library is packaged in two parts: the main part is needed at
runtime by the utilities in this package; and a second "dev" package is required
for any code that wants to compile and built using this library. The "dev"
package contains the header files defining the libraries API amongst other
things.
The library API is relatively stable but is expanded and
sometimes changed in response to changes by www.t10.org . The most recent Debian naming of
this library was libsgutils2-2 . Some other packages depend on this
library.
Shared and static libraries are built by default. To build these
utilities so they don't depend on this shared library use './configure --disable-shared'.
Download and build
Severalrecent versions of the sg3_utils package are listed below. The tarballs contain
README, CHANGELOG (renamed "ChangeLog" in version 1.25), INSTALL, COVERAGE and
CREDITS files plus man pages as well as source and build files. Here is the
most recently released sg3_utils ChangeLog
.
The
sg3_utils-1.31exe.zip file is a zip
archive of Windows executables made in a MinGW environment. Thesg3_utils_man_html.tgz file is a tarball of
man pages converted to html by man2html.
Version 1.25 of sg3_utils adds
an autotools based './configure ; make ;
make install' build system. This replaced the previously hand-crafted
Makefiles that were getting a bit
hard to maintain, especially in ported (i.e. non-Linux) environments. The configure.ac and several Makefile.am files guide the autotools
build. If these files are changed then the './autogen.sh' script should be run. The
autotools based logic builds the code found in the src, lib, include and doc sub-directories. The utils and examples sub-directories still have
hand-crafted Makefiles. If the ./configure or make steps fail then it may be worth
trying to run the './autogen.sh'
script as there are many versions of autotools and the mysterious libtool to be
found. Many options can be given to ./configure and ./configure --help will list many of
those options. By default './configure '
will produce Makefiles that
install under the /usr/local
directory (e.g. executables are placed in the /usr/local/bin directory). To place
executables in the more usual (at least for Linux) /usr/bin directory then use './configure --prefix=/usr ; make ; make
install'.
* tarball also
available with a ".tar.gz" extension and bzipped with a ".tar.bz2" extension.
From version 1.31 the tarball is available with a ".xz" extension as
well.
** Around the time of Fedora
11, RedHat changed their package checksums from MD5 to SHA256. The above rpm
packages are typically built with the most recent Fedora at time of release. It
has been reported that adding "--nomd5" to the rpm command line may help with
unpacking problems. See bug 490613 at RedHat's bugzilla.
*** Some browsers (e.g. firefox) may interpret
a file with an extension of "rpm" as an audio file. In which case press the
right button over the link and select "Save link as ..." to download the
file.
Below is the most recent version of the sg_utils package which
targets the Linux kernel 2.2 series with some support for the lk 2.0 series. No
further work is being done on this package.
| sg_utils version |
tarballs |
rpm source rpms ** |
i386 rpm binaries ** |
| 1.02 | sg_utils-1.02.tgz | sg_utils-1.02-1.src.rpm | sg_utils-1.02-1.i386.rpm |
The
sg3_utils package can be found on http://freshmeat.net .
Return to main page.
Last updated: 16th February 2011
